Who has the best chance to attract new voters?

[dansolo]

I believe the key to winning in 2004 is getting new people to vote. Essentially, for any Democrat to win, they must get voters from key states to tip the balance of electoral votes. There are essentially two sources of these votes:

1. Get Republican voters to switch
2. Get non-voters/third party voters to vote Democratic

There are advantages and disadvantages to each approach. Each voter in the first category essentially counts twice, because in addidtion to adding a vote for the Democrats, it takes a vote away from the Republicans. But, the pool of available voters is much smaller than in the second pool, which amounts to about 50% of potential voters. So which is the best strategy for the Democratic candidate, whomever it is, to use and why?